Back in my SCUBA instructor days.
I had just taken a group for an advanced dive class out to the Coronado islands... a number of students were practicing with underwater cameras. I had completed a shallow dive with them and was sitting on deck when one of the students motioned that a seal seemed to be hanging out near the boat.
I grabbed a mask and fins and dove in... the seal seemed very playful and started to play hide and seek with me... it would dive down to the bottom, and sit and wait until I showed up, then it would surface and go again. Well in short order, I realized I didn't have near the lung capacity of this playful pinniped, so I asked one of the students to rig my gear and throw it in. The water was fairly warm, and shallow, so I didn't bother with the hood.
I quickly slipped on the tank and BC while the seal waited nearby. As soon as I dove down, the seal also dove. The seal would sit on my fins for a moment, then dash off and go into little rock outcroppings and turn around and wait. I followed the little guy to and fro for a half hour... he lead me into little tide pools and through rock openings, and soon a couple of students realized what a photo op this was and joined me and took this picture.
It was probably the most fun I have ever had with a wet suit on. GRIN